porphyrin
The definitions used in this glossary of terminology either have been provided by the authors of the articles, or have been extracted wholly or in part, or paraphrased from the following sources: The American Medical Association Encyclopedia of Medicine, Charles B. Clayman, MD, Medical Editor, Random House, New York, 1989; Biotechnology from A to Z, 2d Edition, William Bains, Oxford University Press, New York, New York, 2002; A Dictionary of Genetics, 6th Edition, Robert C. King and William D. Stansfield, Oxford University Press, New York, New York, 2002; Dorland's Illustrated Medical Dictionary, 29th and 30th Editions, W. B. Saunders Company, Philadelphia, 2000, 2003; Genes VII, Benjamin Lewin, Oxford University Press, New York, New York, 2000; The Gale Encyclopedia of Genetic Disorders, Volumes I and II, Stacey L. Blachford, Ed., Thomson Learning, New York, New York, 2002; The Merriam-Webster Dictionary, Merriam-Webster, Inc., Springfield, Massachusetts, 1997; Molecular Biology of the Cell, 3rd Edition, Bruce Alberts, et al., Garland Publishing, 1994; The Random House Dictionary of the English Language, Unabridged Edition, 1966; Webster's Ninth New Collegiate Dictionary, 1991.
DEFINITION:
- porphyrin
-
Any of a group of compounds containing the porphin structure, four pyrrole rings connected by methylidyne bridges in a cyclic configuration, to which a variety of side chains may be attached. The nature of the side chains is indicated by a prefix, such as coproporphyrin, etioporphyrin, hematoporphyrin, mesoporphyrin, protoporphyrin, or uroporphyrin. Structural isomers are indicated by roman numerals. Free porphyrins are rarely found in tissues except in disorders of heme biosynthesis (porphyrias), but they do occur in the prosthetic groups of hemoglobin, myoglobin, and cytochromes, complexed with metal ions. The term is sometimes used to include porphin or to denote porphin specifically.
Used in 12 Term definitions
Used in 12 Term definitions